International Journal of Computing Science and Applied Mathematics
(IJCSAM) International Journal of Computing Science and Applied Mathematics is an open access journal publishing advanced results in the fields of computations, science and applied mathematics, as mentioned explicitly in the scope of the journal. The journal is geared towards dissemination of original research and practical contributions by both scientists and engineers, from both academia and industry.
Articles
155 Documents
<![CDATA[Prediction of the Number of Passengers at Yogyakarta Airport ]]>
<![CDATA[Imam Safawi Ahmad]]>;
<![CDATA[Agus Suharsono]]>;
<![CDATA[Elly Pusporini]]>
<![CDATA[ (IJCSAM) International Journal of Computing Science and Applied Mathematics Vol 5, No 2 (2019) ]]>
Publisher : <![CDATA[Institut Teknologi Sepuluh Nopember ]]>
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DOI: 10.12962/j24775401.v5i2.5906
<![CDATA[The development of air transportation services is growing up. Based on the report of Central Bureau of Statistics (BPS) in January-October 2015, the number of passengers reached 67.5 million. This number is increased by 12.8% from the previous year with only 58.9 million. Overall, there was increased in the number of passengers caused overload of capacity. One of international airports in Indonesia is Adisutjipto in Yogyakarta. The airport officer wants to develop in terms of airplane schedule management and the number of aircrafts used to calculate the number of passengers in the future. In this study, we aimed to forecast next period by using three methods, namely ARIMA, Exponential Smoothing and Combination of both univariate models. This research gives results that generally all route significantly increased every year with Denpasar, Jakarta, Pontianak and Singapore as exception. They were declined slightly in 2015. The number of passengers of departure and arrival routes are affected by seasonal impact. In addition, the model for departure and arrival data had similar models. Another result is combination method did not produce better results than the univariate method. The fit model for predicting data passenger is ARIMA seasonal methods.]]>
<![CDATA[Second Refinement of Jacobi Iterative Method for Solving Linear System of Equations ]]>
<![CDATA[Tesfaye Kebede Eneyew]]>;
<![CDATA[Gurju Awgichew]]>;
<![CDATA[Eshetu Haile]]>;
<![CDATA[Gashaye Dessalew Abie]]>
<![CDATA[ (IJCSAM) International Journal of Computing Science and Applied Mathematics Vol 5, No 2 (2019) ]]>
Publisher : <![CDATA[Institut Teknologi Sepuluh Nopember ]]>
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DOI: 10.12962/j24775401.v5i2.4311
<![CDATA[In this paper, the new method called second refinement of Jacobi (SRJ) method for solving linear system of equations is proposed. The method can be used to solve ODE and PDE problems where the problems are reduced to linear system of equations with coefficient matrices which are strictly diagonally dominant (SDD) or symmetric positive definite matrices (SPD) or M-matrices. In this case, our new method minimizes the number of iterations as well as spectral radius and increases rate of convergence. Few numerical examples are considered to show the efficiency of SRJ over Jacobi (J) and refinement of Jacobi (RJ) methods.]]>
<![CDATA[Scheduling Of The Crystal Sugar Production System in Sugar Factory Using Max-Plus Algebra ]]>
<![CDATA[Desi Indriyani]]>;
<![CDATA[Subiono Subiono]]>
<![CDATA[ (IJCSAM) International Journal of Computing Science and Applied Mathematics Vol 2, No 3 (2016) ]]>
Publisher : <![CDATA[Institut Teknologi Sepuluh Nopember ]]>
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DOI: 10.12962/j24775401.v2i3.2092
<![CDATA[Sugar is the main trading commodity besides as basic human needs and be a source of energy and mostly traded in the form of solid crystals of sucrose or crystal sugar with cane as raw materials. Sugar production process is very complicated because it had to pass through various stages that require considerable time. The number of machines used in production system affects the complexity in the calculation of production scheduling. In addition, if there are errors in analyzing the operating time that is different for each product, it will cause a chaos in the production scheduling. These conditions encourage us to conduct a study on the production flow or flow lines with buffer. The buffer is used on multiple processors as a placeholder for semi-finished material before it is processed in the next processors. Buffers are used in the form of vessels with varying volume. In this study, the max-plus algebra is the method used to obtain crystal sugar production scheduling system in the sugar factory. From the flow lines that have been made then we derive a model of max-plus algebra to obtain a production schedule that starts with the milling process to obtain crystal sugar. Based on the max-plus algebra model, we also obtained sugar output schedule and some kind of waste. In addition, we obtained two periodicities of each processor, that is from milling processor until sulfitation of thick juice processor with periodicity 177.64 minutes and from vacuum pan A processor until mixer D2 processor with periodicity 1592.63 minutes, from these periodicities, we obtain a periodic production schedule for each processor.]]>
<![CDATA[Weight Optimization of Optimal Control Influenza Model Using Artificial Bee Colony ]]>
<![CDATA[Dinita Rahmalia]]>;
<![CDATA[Teguh Herlambang]]>
<![CDATA[ (IJCSAM) International Journal of Computing Science and Applied Mathematics Vol 4, No 1 (2018) ]]>
Publisher : <![CDATA[Institut Teknologi Sepuluh Nopember ]]>
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DOI: 10.12962/j24775401.v4i1.2997
<![CDATA[Influenza is disease which can be contagious through contact with infected individual. There are two types of control strategies to bound the spread of disease: prevention action for controlling susceptible and treatment for controlling infected. Optimal control is used for minimizing the number of infected individual, the cost of prevention action and the cost of treatment. Due to the cost of objective function depends on weight, in this research we will apply Artificial Bee Colony algorithm to optimize weight minimizing cost of objective function. The simulations show that the number of infected with control is lower than without control. Furthermore, we also obtain optimal weight related to cost of prevention action and treatment.]]>
<![CDATA[Comparison of Numerical Methods on Pricing of European Put Options ]]>
<![CDATA[Mardianto, Lutfi]]>;
<![CDATA[Pratama, Aditya Putra]]>;
<![CDATA[Soemarsono, Annisa Rahmita]]>;
<![CDATA[Hakam, Amirul]]>;
<![CDATA[Putri, Endah Rokhmati Merdika]]>
<![CDATA[ (IJCSAM) International Journal of Computing Science and Applied Mathematics Vol 5, No 1 (2019) ]]>
Publisher : <![CDATA[Institut Teknologi Sepuluh Nopember ]]>
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DOI: 10.12962/j24775401.v5i1.3172
<![CDATA[Put option is a contract to sell some underlying assets in the future with a certain price. On European put options, selling only can be exercised at maturity date. Behavior of European put options price can be modeled by using the Black-Scholes model which provide an analytical solution. Numerical approximation such as binomial tree, explicit and implicit finite difference methods also can be used to solve Black-Scholes model. Some numerical methods are applied and compared with the analytical solution to determine the best numerical method. The results show that numerical approximations using the binomial tree is more accurate than explicit and implicit finite difference method in pricing European put options. Moreover when the value of T is higher then the error obtained is also higher, while the error obtained is lower when the value of N is higher. The value of T and N cause the increase of the computation time. When the value of T is higher the computation time is lower, while computation time is higher if the value of N is higher. Overall, the lowest computation time is obtained by using an explicit finite difference method with an exceptional as the value of T is big and the value of N is small. The lowest computation time is obtained by using a binomial tree method.]]>
<![CDATA[Error Modeling Radar Rainfall Estimation Through Incorporating Rain Gauge Data Over Upper Blue Nile Basin, Ethiopia ]]>
<![CDATA[Megbar Wondie Birhan]]>;
<![CDATA[U. Jaya Prakash Raju]]>;
<![CDATA[Samuel T. Kenea]]>
<![CDATA[ (IJCSAM) International Journal of Computing Science and Applied Mathematics Vol 5, No 2 (2019) ]]>
Publisher : <![CDATA[Institut Teknologi Sepuluh Nopember ]]>
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DOI: 10.12962/j24775401.v5i2.4687
<![CDATA[Accurate and precise measurements of rainfall from weather radar reflectivity data is essential to supplement the limited characterization of spatial and temporal measurements provided by insufficient network and density of rain gauges. While weather radar has high spatial and temporal resolution, it contaminated with various sources of errors due to the conversion of reflectivity to rain rate and the projectile rainfall motion. Error modeling improvement with the application of projectile rainfall motion correction is essential to improve the radar data. However, stile is not well documented for over the world as well as Ethiopia. Therefore, the aim of this study was to generate an error model for weather radar rainfall estimation by incorporating gauge rainfall data over upper Blue Nile basin, Ethiopia. Projectile rainfall motion correction is considered on the data of reflectivity and rain rate to determine empirical error model parameter values. The model parameter values are found, multiplicative factor (a) was 55, the exponent factor (b) was 1.12, standard deviation of proportional error was 0.08 and standard deviation of random error was 0.07. The value of the total error varied from -0.45 to 1.16 mm and the domain of proportional error was greater than random error. After applying the projectile rainfall motion correction, the total error is reduced by 12%. In general, the assumption of projectile method is quite useful for improving the radar data over upper Blue Nile basin in Ethiopia as well as over the world. Hence, we wish to extend this method for other regions.]]>
<![CDATA[Optimal Control of Multi-Supplier Inventory Management with Lead Time ]]>
<![CDATA[Darsih Idayani]]>;
<![CDATA[Subchan Subchan]]>
<![CDATA[ (IJCSAM) International Journal of Computing Science and Applied Mathematics Vol 6, No 1 (2020) ]]>
Publisher : <![CDATA[Institut Teknologi Sepuluh Nopember ]]>
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DOI: 10.12962/j24775401.v6i1.5040
<![CDATA[In the current global competition, companies are required to save money in order to survive. One of the expenses that can be reduced is the cost of inventory control. To minimize these costs, we require a proper planning and management of the inventory. Ordering supplies should be performed at a certain time period, especially with uncertain demand. As such, the company must determine when to order at the suppliers and how many should be ordered. So there will be no excess inventory in the warehouse because of too much ordering or because of the inventory cannot meet demand due to late or too little order to suppliers. Consequently, in this research, a quadratic cost functional is used as the objective function in multi-supplier inventory management problem with different lead time. Optimal control theory, LQR (Linear Quadratic Regulator) is used to solve this problem. According to the simulation, we conclude that the smaller weight resulted in more optimal inventory cost.]]>
<![CDATA[Bifurcation Analysis of Toxoplasmosis Epidemic Control on Increased Controlled Rate of Suppressing the Rate of Infected Births ]]>
<![CDATA[Meri Hari Yanni]]>;
<![CDATA[Zulfahmi Zulfahmi]]>
<![CDATA[ (IJCSAM) International Journal of Computing Science and Applied Mathematics Vol 6, No 1 (2020) ]]>
Publisher : <![CDATA[Institut Teknologi Sepuluh Nopember ]]>
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DOI: 10.12962/j24775401.v6i1.5978
<![CDATA[The toxoplasmosis epidemic is an infectious disease caused by the parasitic Toxoplasma Gondii. This disease attacks the human immune system and other organs in the body, resulting in damage to tissues. The spread of the disease is carried out in various ways, one of them is eating foods that are less hygienic or not cooked properly, resulting in parasites remain active. Provision of controlled therapy is one solution in controlling the epidemic against suppression of the birth rate infected with toxoplasmosis. This study discusses the bifurcation analysis of a mathematical model for controlling the toxoplasmosis epidemic. Bifurcation analysis is carried out on the controlled rate and rate of birth control of toxoplasmosis. From the mathematical model of controlling the toxoplasmosis epidemic, stability and existence analysis are performed at each equilibrium point. Next, a function of two independent parameters is constructed which influences the spread of the disease, namely the controlled rate and the rate of infected births. Then, a bifurcation analysis of each region is obtained from each function of the two free parameters. From the bifurcation analysis, three regional conditions were obtained which showed the dynamics of the toxoplasmosis epidemic of two independent parameters with each interpretation of the bifurcation region.]]>
<![CDATA[Handling Imbalance Data in Classification Model with Nominal Predictors ]]>
<![CDATA[Kartika Fithriasari]]>;
<![CDATA[Iswari Hariastuti]]>;
<![CDATA[Kinanthi Sukma Wening]]>
<![CDATA[ (IJCSAM) International Journal of Computing Science and Applied Mathematics Vol 6, No 1 (2020) ]]>
Publisher : <![CDATA[Institut Teknologi Sepuluh Nopember ]]>
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DOI: 10.12962/j24775401.v6i1.6643
<![CDATA[Decision tree, one of classification method, can be done to find out the factors that predict something with interpretable result. However, a small and unbalanced percentage will make the classification only lead to the majority class. Therefore, handling imbalance class needs to be done. One method that often used in nominal predictor data is SMOTE-N. For accuracy improving, a hybrid SMOTE-N and ADASYN-N was developed. SMOTE-N-ENN and ADASYN-N were developed for accuracy improvement. In this study, SMOTE-N, SMOTE-N-ENN and ADASYN-N will be compared in handling imbalance class in the classification of premarital sex among adolescent using base class CART. The conclusion obtained regarding the best method for handling class imbalance is ADASYN-N because it provides the highest AUC compared to SMOTE-N and SMOTE-N-ENN. The best decision tree provides information that factors that can predict adolescents having premarital sexual relations are dating style, knowledge of the fertile period, knowledge of the risk of young marriage, gender, recent education, and area of residence.]]>
